If there is a choice regarding an inheritance, I think it would come nearer the end as it'd probably be easier to create branching endings than it would be to create branching paths in the middle of the story where he either does or doesn't have the money.
What I could see happening at this point in the story is that his family, most likely grandparents, would like to meet with him to apologise for what happened with his Mom (them essentially disowning her) and to tell him they want to get to know him and have him be part of their family. They'd then inform him of a bank account they've opened in his name which he's free to use if he wants to and these small decisions could be scattered throughout the rest of the game (i.e. offer to pay Maya's tuition, help Quinn out, pay for things for the DIKs, etc), and then at the end of the game the MC has to decide whether to embrace his birth family and keep the money, or reject them and their money for his other family that's comprised of all his friends.
An ending like that would tie in to the opening monologue about the nature of family and how it doesn't always mean that the people you share a blood bond with are your true family.
My guess is at the end of next episode the MC will open the letter. We might not get to read the contents, and that will be left for a episode 3 cliffhanger. Then that will be the launching point of episode 3.
Based on the launguage used by the MC in episode 5 I wonder if the DIK/ CHICK major choices will be retired and you are what you are at this point. He says he has to stop just reacting and think about his choices. Only a few more you can make before crossing the halfway point anyway.
That could mean that the money then becomes a deciding factor. Are you generous or foolish. Do you rebuild the mansion or fix up your Dads house. Pay Maya's tuition or or for a special service from the HOTs. Do pay to go to the Pink Rose or help the HOTs so they don't have to hook. Do you pay to help Bella get professional help after her inevitable mental breakdown or pay to have Quinn sit on your face everynight (LoL).
The thing about Quinn is that she is very much going the way of a character that as soon as she is free from the point of pressure she will continue and aim for more, she will keep digging her grave even deeper... so I think that she will be a tragic character in the sense that either she will ultimately get caught in her problems to a point of no escape or she will be abandoned by everyone or drag someone in her place, and I very much see Riona being the victim here
"Ma ma ma myyy Riona"
Quinn is Darth Vader. Someone else is the emperor. Perhaps Vinny. I think we'll see her plans unravel and her get more and more desperate. As it stands we know, Quinn, Rinoa, Sarah, Melanie, Camila are involved in the prostitution. From what we can gather Heather isn't, nor is Elana but they both know about the drugs (they use and are in the room when Tommy talks to Quinn about it. Arieth doesn't really matter one way or another. It's not clear what Sage knows. Possibly about the prostituion but not about the drugs.
What then becomes interesting is the Daughters. Mona is out and I can't see Ashley getting involved. Lily and camila probably will. Maya is interesting. I think if you don't warn her she will end up getting blackmailed into it. Also a fair chance Josy might be become a stripper.
The voice in my head that likes NTR makes me think twice about warning Maya.
The problem then comes is where does the MC fall in with this and just how complex can DPC make the branching story. There are very few versions of the MC who would let Maya go off the deepend, either because they love her, are her friend or simply because Derek is thier bro. Hmmm so many possibilities.
Final note, I still think there is a resonable chance that Jill ends up being MCs aunt. I think in that sort of context, especially if they end things after finding out it wouldn't be a probelm on patreon. Game of Thrones spent the last 3 seasons with the Aunt/ Nephew relationship being the main romantic one.